System and method for monitoring packer conditions

ABSTRACT

A system and method for monitoring a device in a well, according to which a sensor is embedded in the device for sensing a condition of the device, and outputting a signal in response to the condition.

BACKGROUND

[0001] Downhole packers are commonly used in many oilfield applications for the purpose of sealing against the flow of fluid to isolate one or more portions of a wellbore for the purposes of testing, treating, or producing the well. The packers are suspended from a tubing string, or the like, in the wellbore, or in a casing in the wellbore, and are activated, or set, so that one or more packer elements engage the inner surface of the wellbore or casing. In these arrangements, it is desirable to know how the packer elements react to the packer setting operation and, after the packer is installed, how the various downhole conditions affect the packer.

[0002] Accordingly, what is needed is a system and method for monitoring the packer conditions under the above circumstances.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The drawing is a diagrammatic view of a packer and a monitoring system according to an embodiment of the invention.

DETAILED DESCRIPTION

[0004] Referring to FIG. 1, a downhole tool is referred to, in general, by the reference numeral 10 and is shown installed in a casing 12 disposed in a well. The well can be either a cased completion as shown in the drawing or an openhole completion. The tool 10 is lowered to a predetermined depth in the casing 12 as part of a workstring, or the like, (not shown) which often includes other tools used to perform various oil recovery and completion operations. Since the tool 10 is conventional, it will not be described in detail.

[0005] The tool 10 includes a packer that consists of an annular packer element 14 and an annular slip 16 located downstream and slightly spaced from the packer element 14. The packer element 14 is located at a predetermined axial location in the casing 12 and is set, or activated, in a conventional manner which causes it to engage the inner surface of the casing 12 to seal against the flow of fluids and thus permit the isolation of certain zones in the well. Also, the slip 16 is set, or activated, so as to “bite” into the inner surface of the casing 12 to anchor the packer to the casing 12. Since both the packer element 14 and the slip 16 are conventional, they will not be described in further detail.

[0006] A plurality of sensors 20, four of which are shown in the drawing, are embedded in the packer element 14. If the packer element 14 is injection molded, the sensors 20 can be formed into the packer element 14 by suspending the sensors 20 in a packer element mold with a mechanical holding device, such as a small diameter rod, or wire, which can be withdrawn after the mold is filled with an elastomeric material, but before the elastomeric material has set. If the packer element 14 is formed by an elastomeric component, such as is the case with inflatable packer elements which are formed in a “lay-up” process, the sensors 20 can be placed into the layered-up structure at the appropriate depth between layers as the construction process progresses.

[0007] As shown in the drawing, the sensors 20 can be placed at various locations in the packer element 14 and can be both axially spaced and radially spaced relative to the packer element 14.

[0008] The sensors 20 can be fabricated according to one of several high temperature fabrication processes similar to those used in fabricating integrated circuits. For example, a conventional insulated, bulk, complementary metal-oxide-silicon process, using silicon-on-insulator fabrication technologies, can be used. Also, the embedded sensors 20 and their associated circuits can be constructed using known silicon-on-sapphire fabrications processes.

[0009] The sensors 20 can be designed to sense one or more of several parameters, or conditions, associated with the packer element 14, including, but not limited to, pressure at different areas in the packer element 14, local strain in the packer element 14, shear forces in the packer element 14, creep in the packer element 14, chemical conditions in the packer element 14, as well as any measurement which can be taken more effectively from within the packer element 14 when compared to measurements taken outside the packer element 14.

[0010] An electronics package is shown, in general, by the reference numeral 24 and includes a transceiver 26 and appropriate electrical conductors and associated electronics (not shown) electrically connecting the sensors 20 and the transceiver 26, and extending from the transceiver 26 to the earth's surface for connection to appropriate electronics, which can include a computing device, and the like (not shown). It is understood that the transceiver 26 may be, for example, a power and data transceiver, and may contain built-in processing capability that can be used to process the signals from the sensors 20 downhole to determine specific packer element 14 parameters. The transceiver 26 can also be used to transmit processed or raw signals, via a telemetry system, to the earth's surface or to another location within the well. The telemetry system can be, but is not limited to, hardwire, acoustic, EM or mud pulse systems.

[0011] In operation, signals from the sensors 20, which correspond to one or more of the parameters set forth above, are inputted to the transceiver 26 which processes the signals as discussed above and outputs the signals, or corresponding signals, to the above-mentioned computing device and its associated electronics at the earth's surface. The computing device can then initiate corrective measures to compensate for any predetermined deviation from a standard value set for the particular parameter.

Variations and Equivalents

[0012] It is understood that several variations may be made in the foregoing without departing from the scope of the invention. For example, the present invention is not limited to sensing one or more or the above-specified conditions, or parameters, but is equally applicable to other parameters consistent with the operation of the packer. Also, the sensors can be embedded in other downhole components utilized in subsurface oil and gas recovery operations, including, but not limited to, packer slips, bridge plugs, etc. Further, the number of packer elements, slips, and sensors can be varied within the scope of the invention. Also, it is understood that spatial references, such as “axially”, “radially”, “downstream”, etc. are for the purpose of illustration only and do not limit the specific spatial orientation or location of the components described above.

[0013] Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many other modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. 

What is claimed is:
 1. A system for monitoring a device in a well, the system comprising a sensor embedded in the device for sensing a condition of the device and for outputting a signal in response to the condition.
 2. The system of claim 1 further comprising a transceiver for receiving the signal from the sensor and processing the signal.
 3. The system of claim 1 wherein the condition is selected from the group consisting of pressure at at least one area in the device, local strain in the device, shear forces in the device, creep in the device, and chemical conditions in the device.
 4. The system of claim 1 wherein the condition is such that it is measured more effectively from within the device when compared to measurements taken outside the device.
 5. The system of claim 1 wherein the sensor is fabricated according to an insulated, bulk complementary metal-oxide-silicon process, using high-temperature silicon-on-insulator technologies.
 6. The system of claim 1 wherein the device is a packer.
 7. The system of claim 6 wherein the packer comprises an elastomeric packer element, and wherein the sensor is embedded in the elastomeric packer element.
 8. The system of claim 1 wherein the sensor is fabricated using a silicon-on-sapphire fabrication process.
 9. A method for monitoring a device in a well, the method comprising the steps of: embedding a sensor in the device for sensing a condition of the device; and outputting a signal from the sensor in response to the condition.
 10. The method of claim 9 further comprising the step of transmitting the output signal from the sensor to a transceiver for processing.
 11. The method of claim 9 wherein the condition is selected from the group consisting of pressure at at least one area in the device, local strain in the device, shear forces in the device, creep in the device, and chemical conditions in the device.
 12. The method of claim 9 wherein the condition is such that it is measured more effectively from within the device when compared to measurements taken outside the device.
 13. The method of claim 9 wherein the sensor is fabricated according to an insulated, bulk complementary metal-oxide-silicon process, using high-temperature silicon-on-insulator technologies.
 14. The method of claim 9 wherein the device is a packer.
 15. The method of claim 14 wherein the packer comprises an elastomeric packer element, and wherein the sensor is embedded in the elastomeric packer element.
 16. The method of claim 9 wherein the sensor is fabricated using a silicon-on-sapphire fabrication process. 